What's up with Chrono lords final 15% phase?

Seems brutal. Seems to be a heavy healer check. We had the dk tank kill the last 7% by himself somehow. The boss barely took damage and we were all 435+. It felt like a raid boss practically, is there a trick to somehow taking less damage in that phase or something we missed? Or is it one of those “overtuned” bosses right now?

Having just done it, it is intense healing wise, but honestly it was so much fun! First fight this season I actually went oom. Gonna have to work on that, I probably had more over healing than was necessary.

Kudos to blizzard for the infinite dragon skins. My slitherdrake looks amazing!

Edit: there is a magic dot that does heavy ticking damage that can overlap with the tank frontal. If you have dps in the group that can dispel magic that would help the healer out a lot. That tank frontal requires pumping heals. At least it did for us.